We present a setting for the study of torsion theories in general categories. The idea is to associate, with any pair ($\mathcal T$, $\mathcal F$) full replete subcategories category C$, corresponding subcategory Z = \mathcal T \cap F$ \emph{trivial objects} C$. morphisms which factor through Z$ are called Z$-trivial, and these form an ideal morphisms, respect one can define Z$-prekernels, Z$-p...

Formal speciication of software requirements has been recognised as an essential ingredient to improve the quality of delivered code. When integrated with the structuring mechanisms of object-orientation, formal spec-iications can provide a powerful tool for the software developer. However, the formal speciication of particularly large systems needs to be supported by tools which assist the spe...

We use a novel technique to simulate the growth of one of the most massive progenitors of a supercluster region from redshift z ∼ 80, when its mass was about 10M⊙, until the present day. Our nested sequence of N–body resimulations allows us to study in detail the structure both of the dark matter object itself and of its environment. Our effective resolution is optimal at redshifts of 49, 29, 1...

We use a novel technique to simulate the growth of the most massive progenitor of a protocluster region from redshift z ∼ 80, when its mass was about 10M⊙, until the present day. Our nested sequence of N–body resimulations allows us to study in detail the structure both of the dark matter object itself and of its environment. Our effective resolution is optimal at redshifts of 49, 29, 12, 5 and...

For analytic functions f(z) and g(z) which satisfy the subordination f(z) ≺ g(z), J. E. Littlewood (Proc. London Math. Soc., 23 (1925), 481–519) has shown some interesting results for integral means of f(z) and g(z). The object of the present paper is to derive some applications of integral means by J.E. Littlewood and show interesting examples for our theorems. We also generalize the results o...

The integration of several different modelling techniques into a single formal method has turned out to be advantageous in the formal design of software systems. Giving a semantics to an integrated formal method is currently a very active area of research. In this paper we discuss the advantages of a failure-divergence semantics for data and process integrating formal methods, in particular for...

This paper provides a precise and descriptive semantics for core modeling concepts in Object-Z and a formal description for UML class constructs. Given the formal descriptions, it also provides a formal semantic mapping between the modeling constructs of the two languages.

Modeling arbitrary real objects is difficult and rendering textured models typically does not result in realistic images. We describe a new method for displaying scanned real objects, called view-based rendering. The method takes as input a collection of colored range images covering the object and creates a collection of partial object models. These partial models are rendered separately using...

Open network management is assisted by representing the system resources to be managed as objects, and providing standard services and protocols for interrogating and manipulating these objects. Application of formal techniques can make the speciications more precise, reducing the ambiguity inherent in natural language, and can automate some or all of the process of implementation and testing. ...

In this paper we demonstrate usability analysis of Object-Z user-interface designs. Usability can be defined in terms of five salient properties of an interactive system: task efficiency, reuse, user-computer communication, robustness and flexibility. Formal user-interface designs have been touted as a basis for determining the usability of an interactive system prior to the expense of system d...